<!DOCTYPE html>
<html lang="en">
<head>
    <meta charset="utf-8"/>
    <link rel="icon" href="%PUBLIC_URL%/favicon.ico"/>
    <meta name="viewport" content="width=device-width, initial-scale=1"/>
    <meta name="theme-color" content=""/>
    <meta name="description" content=""/>
    <title>React App</title>
</head>
<body>
<span id="txtBox">0</span>
<br>
<button id="sumbit">累加</button>
<script>
    let a = 1
</script>
</body>
</html>
